Introduction and Context
Cutaneous squamous cell carcinoma (CSCC) is among the most common skin cancers and typically behaves indolently. However, a subset of tumors is at appreciable risk for regional nodal or distant metastasis, and imaging can alter management for those patients. Until recently, professional guidance offered broad, non-specific imaging recommendations that left clinicians uncertain about which patients should undergo staging or surveillance imaging, which modalities to choose, and how long to continue surveillance.
A new multidisciplinary expert consensus published in JAMA Dermatology (Kassamali et al., 2026) addresses that need. Using a structured Delphi process with 45 experts from dermatology, medical oncology, radiation oncology, radiology, surgery and otolaryngology, the panel generated practical recommendations on when to obtain staging and follow-up imaging in localized CSCC, which modalities to use, and appropriate surveillance duration. The consensus aims to reduce variability in practice, align imaging use with metastatic risk, and inform future formal guideline updates.
Why this consensus matters now
– National guidance (for example, National Comprehensive Cancer Network, NCCN) has been intentionally broad, reflecting heterogeneous evidence. That has produced wide variation in imaging usage across institutions and clinicians.
– New data and clinical experience show that imaging can meaningfully change staging, treatment planning, and outcomes in higher-risk CSCC, but unnecessary imaging increases cost, exposes patients to radiation, and may produce false positives that lead to invasive procedures.
– The Delphi consensus provides an evidence-informed, pragmatic threshold-based approach that clinicians can apply at the point of care.
New Guideline Highlights
Major takeaways from the Kassamali et al. (2026) consensus include:
– A practical metastasis-risk threshold for imaging: the panel recommended staging and surveillance imaging for tumors with an estimated risk of metastasis of at least 15%.
– Specific high-risk anatomic and histologic features that meet the threshold for imaging: concern for metastasis on exam, bone invasion, invasion beyond subcutaneous fat, large-caliber nerve invasion, tumor diameter ≥4 cm, and several combined-risk scenarios involving poor differentiation, lymphovascular invasion (LVI), subcutaneous fat invasion, and perineural invasion (PNI).
– Preferred modality: Computed tomography (CT) was the consensus-preferred imaging modality for nodal staging and surveillance (84% and 78% agreement, respectively).
– Surveillance duration: consensus for at least 2 years of imaging follow-up, with near consensus supporting at least 3 years.
Key implications for clinicians
– The consensus translates risk markers into concrete imaging triggers so clinicians can better judge when imaging will likely add value.
– Emphasizing CT for nodal imaging while reserving MRI for suspected perineural or skull-base involvement reflects pragmatic balances of availability, sensitivity, and cost.
Updated Recommendations and Key Changes
How this consensus differs from prior guidance
– From broad to specific: Prior statements (including NCCN guidance) suggested clinicians consider imaging for ‘‘high-risk’’ CSCC without consistently defining which combinations of features should prompt imaging. The Delphi panel specified objective anatomic and histologic thresholds tied to a ≥15% metastasis risk.
– Modality preference clarified: While previous guidance left modality choice to clinician judgment, the panel identified CT as the preferred initial modality for nodal staging/surveillance, with MRI reserved for select scenarios (e.g., clinical or radiographic concern for perineural spread or skull-base involvement).
– Defined surveillance window: The consensus gives a minimum imaging surveillance period (2 years) rather than leaving duration entirely open-ended.
Table — Key changes vs prior practice (summary)
– Prior guidance: ‘‘Consider imaging for high-risk tumors; modality and duration variable.’n- Delphi consensus: Imaging recommended when estimated metastasis risk ≥15%; clear list of tumor features that meet threshold; CT preferred for nodal staging/surveillance; imaging at least 2 years, consider 3 years.
Evidence informing updates
– The panel used a structured Delphi process incorporating clinical expertise, relevant literature about CSCC risk factors and imaging yield, and practical considerations (availability, radiation, cost). Supporting background sources include AJCC staging criteria and longstanding epidemiologic data on metastasis risk, as well as contemporary institutional series demonstrating that imaging can alter staging and management in selected high-risk lesions.
References underpinning the consensus (select)
– Kassamali B, Schoenfeld JD, Sethi R, et al. Consensus Guidelines for Staging and Surveillance Imaging in Cutaneous Squamous Cell Carcinoma. JAMA Dermatol. 2026. PMID: 42418212.
– Amin MB, Edge SB, Greene FL, et al., editors. AJCC Cancer Staging Manual. 8th ed. Springer; 2017.
– National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Squamous Cell Skin Cancer. NCCN.org (current versions).
– Rowe DE, Carroll RJ, Day CL Jr. Prognostic factors for local recurrence, metastasis, and survival rates in squamous cell carcinoma of the skin, ear, and lip. J Am Acad Dermatol. 1992;26(2 Pt 1):976–990.
Topic-by-Topic Recommendations
Below are distilled, actionable recommendations from the consensus presented by topic.
When to obtain staging imaging (initial workup)
The panel recommended staging imaging for localized CSCC when any of the following are present (consensus or near-consensus):
– Clinical concern for metastasis (palpable or suspicious lymphadenopathy, symptoms suggesting regional spread).
– Bone invasion on exam or biopsy.
– Tumor invasion beyond subcutaneous fat.
– Large-caliber nerve invasion (clinical or radiographic evidence).
– Tumor diameter ≥4 cm.
– Poorly differentiated histology combined with any of these three: diameter ≥2 cm; lymphovascular invasion (LVI) plus subcutaneous fat invasion; or LVI plus small-caliber perineural invasion (PNI).
The panel operationalized these features as meeting an estimated metastasis risk threshold of ≥15% — the value at which imaging was generally recommended.
Which imaging modality to choose
– CT with contrast (neck/chest/abdomen/pelvis as clinically indicated) was the panel’s preferred modality for initial nodal staging and interval surveillance owing to broad availability and robust assessment of lymph node enlargement and pulmonary metastases.
– MRI was recommended when perineural invasion or skull-base involvement was suspected (superior soft-tissue and neural canal resolution).
– PET/CT may be considered selectively for patients with high-risk features when there is concern for occult distant disease or when CT findings are equivocal; panelists noted PET/CT’s higher sensitivity for metabolically active distant metastasis but also higher false-positive rates and cost.
– Ultrasound with fine-needle aspiration can be useful for targeted evaluation of suspicious regional lymph nodes.
Surveillance imaging: frequency and duration
– Consensus: perform imaging for at least 2 years after definitive local therapy for tumors meeting imaging criteria.
– Near-consensus: consider extending imaging surveillance to at least 3 years in selected higher-risk patients (for example, persistent immunosuppression, multiple high-risk features, or incomplete resection margins).
– Surveillance intervals should be individualized (e.g., imaging every 3–6 months in the first 1–2 years for very high-risk patients, then spacing out if negative), balancing recurrence risk and harms of imaging.
Special populations and caveats
– Immunosuppressed patients (solid organ transplant recipients, chronic immunosuppression): experts emphasized individualized lower thresholds for imaging because these patients carry higher metastatic risk; many panelists favored earlier or more prolonged surveillance, though exact thresholds varied.
– Head and neck tumors with clinical suspicion of perineural invasion: MRI is preferred; consider contrast-enhanced, dedicated neuroanatomic sequences.
– Patients with suspected bone invasion: CT and MRI may be complementary — CT for cortical bone evaluation, MRI for marrow and soft-tissue extent.
Practical recommendation checklist for clinicians
– Assess tumor for predefined high-risk features (see list above). If any criterion is met, discuss staging imaging.
– Start with contrast-enhanced CT for nodal staging and chest evaluation, add MRI for suspected perineural or skull-base disease.
– For confirmed nodal metastasis on imaging, refer promptly to multidisciplinary care (head & neck surgery, radiation oncology, medical oncology, dermatology).
– Plan imaging surveillance for at least 2 years; individualize interval and duration according to patient risk and clinical course.
Expert Commentary and Insights
How the panel reached agreement
– The Delphi panel included 45 multidisciplinary experts who completed three iterative survey rounds (January–June 2025). Consensus was defined as ≥80% agreement and near-consensus as 70%–79% agreement.
– The multidisciplinary composition (dermatology, radiation and medical oncology, radiology, surgery, otolaryngology) strengthened applicability across practice settings.
Consensus areas and controversies
– Strong consensus: establish an objective metastasis-risk threshold (≥15%) and use CT for initial nodal staging/surveillance in most patients.
– Lesser consensus: exact surveillance intervals were more variable; the panel endorsed a minimum 2-year imaging period but stopped short of a single universally applicable interval schedule.
– Controversy: the role of PET/CT in routine staging for high-risk but clinically node-negative patients remains debated; panelists agreed it may be valuable selectively but not as a first-line universal tool.
Panel perspectives on implementation
– Many experts stressed that these recommendations are intended to reduce underuse in genuinely high-risk patients and to curb overuse in low-risk disease.
– Implementation will require clinician education, local imaging pathways (to streamline CT protocoling for head & neck CSCC), and shared decision-making with patients about the trade-offs of radiation exposure, cost, and potential downstream procedures.
Research gaps identified by the panel
– Prospective studies are needed to validate the 15% metastasis-risk threshold and to quantify how imaging-driven changes in management impact survival and quality of life.
– Comparative effectiveness studies of CT versus PET/CT (and the addition of MRI) in specific CSCC subgroups would inform modality selection and cost-effectiveness.
Practical Implications
For clinicians
– Use the specified high-risk features to trigger imaging discussions and referrals, rather than relying on vaguely defined ‘‘high-risk’’ labels.
– Prioritize CT for nodal and chest staging in most scenarios and reserve MRI for suspected perineural disease.
– Share the rationale for imaging and surveillance duration with patients; document individualized plans, especially for immunosuppressed patients.
For health systems
– Standardized imaging pathways could improve diagnostic yield and streamline multidisciplinary planning.
– Thoughtful use of imaging may reduce unnecessary tests and downstream procedures while ensuring patients with actionable disease are identified early.
A brief patient vignette (illustrative)
– Patient: Maria Thompson, 72, with a 3.5-cm poorly differentiated CSCC on the cheek that invades subcutaneous fat and shows focal lymphovascular invasion on pathology. Using the consensus framework, Maria meets an imaging threshold (poor differentiation plus subcutaneous invasion and LVI) with an estimated metastatic risk ≥15%; contrast-enhanced CT of the neck and chest was recommended for staging. CT identified an enlarged ipsilateral level II node, confirmed by ultrasound-guided fine-needle aspiration. Multidisciplinary discussion led to neck dissection and adjuvant radiotherapy — a management plan altered directly by staging imaging.
Conclusions
The 2026 Delphi consensus offers practical, multidisciplinary, evidence-informed recommendations to standardize staging and surveillance imaging for localized CSCC. By tying imaging to an explicit metastasis-risk threshold (≥15%) and defining concrete tumor features that meet that threshold, the guidance helps clinicians decide when imaging will meaningfully influence care. CT emerged as the preferred initial modality for nodal staging and surveillance, MRI for suspected perineural disease, and a minimum of 2 years of imaging follow-up was endorsed. These recommendations do not replace individualized care but provide a clear framework to reduce variability and focus imaging resources on patients most likely to benefit.
References
– Kassamali B, Schoenfeld JD, Sethi R, et al. Consensus Guidelines for Staging and Surveillance Imaging in Cutaneous Squamous Cell Carcinoma. JAMA Dermatol. 2026 Jul 8. PMID: 42418212. https://pubmed.ncbi.nlm.nih.gov/42418212/
– Amin MB, Edge SB, Greene FL, et al., editors. AJCC Cancer Staging Manual. 8th ed. Springer; 2017.
– National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Squamous Cell Skin Cancer. NCCN.org. (access for current versions and institutional implementation)
– Rowe DE, Carroll RJ, Day CL Jr. Prognostic factors for local recurrence, metastasis, and survival rates in squamous cell carcinoma of the skin, ear, and lip. J Am Acad Dermatol. 1992;26(6):976–990.
